In a wireless communications network, a wireless communication device (WCD) may communicate with a serving node (SN) of a core network (CN) via a radio access network (RAN), such as the evolved UMTS RAN (e-UTRAN).
The WCD may be, e.g., a mobile station (MS) or a user equipment (UE) or a Cellular Internet-of-Things (CIoT) device, such as a mobile phone, laptop or similar device with wireless capability. It may be embedded (e.g., as a card or a circuit arrangement) in and/or attached to various other devices, such as in various laptop or tablet computers, or other mobile consumer electronics, in home appliances, sensors, meters, accentuators, or embedded in vehicles, boats, or airplanes or other transportation devices.
The RAN may cover a geographical area which is divided into cell areas, with each cell area being served by a base station, e.g. a Radio Base Station (RBS). One example of radio access networks is a GSM EDGE Radio Access Network (GERAN). Another example of RANs is a Universal Mobile Telecommunications System (UMTS) Terrestrial RAN (UTRAN), which use a base stations called a “NodeB” or “B node.” The base stations communicate via an air interface with WCDs within range of the base stations. Each base station may cover one of the cell areas. UMTS is a third generation wireless communication system, which evolved from the Global System for Mobile Communications (GSM), and is intended to provide improved mobile communication services based on Wideband Code Division Multiple Access (WCDMA) access technology. Still another example of RANs is an enhanced or evolved UTRAN (e-UTRAN), which uses a base station called an enhanced or evolved NodeB (eNB). These RANs and base stations may be used in LTE systems.
A base station of a RAN may have a base station controller. For UTRANs, the base station controller may be a Radio Network Controller (RNC) or a Base Station Controller (BSC) that is shared by several NodeBs. The NodeBs may be connected by, e.g., landlines or microwave links, to the RNC or BSC. The RNC or BSC may supervise and coordinates various activities of the plurality of base stations connected thereto. For UTRANs, the NodeB may be connected to a GPRS core network. For e-UTRAN, each eNodeB may have a base station controller located in the eNodeB, and may be connected to a core network called an evolved packet core (EPC) network. An example of an e-UTRAN and EPC network of a LTE system is illustrated in FIG. 15, and an example of a UTRAN and GPRS core network of a UMTS system is illustrated in FIG. 16.
The RANs and core networks may be part of a public land mobile network (PLMN) that provides Internet access or other form of network connectivity to a WCD. For instance, Verizon or another service provider or operator may operate a PLMN that deploys a plurality of RANs and core networks to provide Internet connectivity to customers' WCDs.
Examples of a core network include a general packet radio service (GPRS) core network and a evolved packet core (EPC) or system architecture evolution (SAE) core network. As illustrated in FIGS. 15 and 16, these core networks (e.g., core network 240) may include nodes such as a mobility management entity (MME) 241, a Serving Gateway (SGW) 244, a Policy and Charging Rules Function (PCRF) node 246, a Home Subscriber Server (HSS) 243, a Serving GPRS Support Node (SGSN) 242, and/or a network gateway node. The network gateway nodes may provide connectivity for the radio terminals of the communication network to one or more external Packet Data Networks (PDNs). Examples of the network gateway node are the Gateway GPRS Support Node (GGSN) and the PDN Gateway (PGW) 245. Some core networks may be assigned to a specific subscriber or specific set of subscribers, and may be referred to as dedicated core networks (DCNs).
The Mobility Management Entity (MME) 241 is a serving node for a core network in a LTE system. It may be responsible for mobility management, such as idle mode UE tracking and paging procedure, including retransmissions. It may be responsible for session management, such as the bearer activation/deactivation process and the establishing of a PDN connection for a UE. It may be responsible for choosing the SGW 243 for a UE 201 at an initial attach process and at the time of intra-LTE handover involving Core Network (CN) node relocation. It may be responsible for authenticating a user (by interacting with the HSS 243).
In LTE systems, a UE 201 and MME 241 may communicate via Non-Access Stratum (NAS) signaling, which terminates at the MME 241 and may be responsible for generation and allocation of temporary identities to UEs. The MME 241 may check the authorization of the UE 201 to camp on the service provider's Public Land Mobile Network (PLMN) and enforce UE roaming restrictions. The MME 241 may be the termination point in the network for ciphering/integrity protection for NAS signaling and may handle security key management. The MME 241 may also provide the control plane function for mobility between LTE and 2G/3G access networks with the S3 interface terminating at the MME 241 from a SGSN 242. The MME 241 may also terminate the S6a interface towards the home HSS 243 for roaming UEs.
The Serving GPRS Support Node (SGSN) 242 is a serving node for a GPRS core network. It may be responsible for the delivery of data packets from and to radio terminals, such as mobile stations within its geographical service area. Its tasks may include packet routing and transfer, mobility management (attach/detach and location management), session management (e.g., logical link management), and authentication and charging functions. The SGSN may have a location register that stores location information (e.g., current cell, or current Visitor Location Register (VLR)) and user profiles (e.g., International Mobile Station Identity (IMSI)) of all GPRS users registered with this SGSN.
In FIG. 15, the Serving Gateway (SGW) 244 may route and forward user data packets, while also acting as the mobility anchor for the user plane during inter-eNB handovers, and as the anchor for mobility between LTE and other 3GPP technologies, such as those involving UTRAN 217 AND GERAN 218, which may communicate with the SGW 244 via the S4 interface. The PDN Gateway (PGW) 245 is a network gateway node that provides connectivity for the UE 201 to one or more external Packet Data Networks (PDNs) by being the point of exit and entry of traffic for the UE 201. A UE 201 may have simultaneous connectivity with more than one PGW for accessing multiple PDNs. The Policy and Charging Rules Function (PCRF) node 246 may determine policy rules in real-time with respect to the radio terminals of the system. The PCRF node 246 may provide the PGW 245 with such rules and/or policies to be used by the PGW, which may perform a Policy and Charging Enforcement Function (PCEF). The Home Subscriber Server (HSS) 243 is a database that may contain user-related and subscriber-related information. It may also provide support functions in mobility management, call and session setup, user authentication, and access authorization.
In a GPRS core network, the Gateway GPRS Support Node (GGSN) is a network gateway node that provides connectivity for radio terminals such as UEs or MSs to one or more external Packet Data Networks (PDNs) by being the point of exit and entry of traffic for the radio terminal. The GGSN may be responsible for the interworking between the GPRS network and one or more external Packet Data Networks (PDNs), like the Internet and X.25 networks. The GGSN may be the anchor point that enables the mobility of the user terminal in the GPRS/UMTS networks.
Wireless networks may be used to support Internet-of-Things (IoT), which involves a network of physical objects such as indoor appliances, sensors, medical devices, and other devices with, e.g., wireless communication capability. The wireless network may be a cellular-based network such as a UMTS or LTE network, and may be part of a Cellular Internet-of-Things (CIoT) system.
A plurality of dedicated core networks (DCNs) may exist as candidates to communicate with CIoT devices. One study has proposed having an eNB select from among the DCNs based on a “UE usage type” parameter that is passed to the eNB from a UE. This study is discussed in SA WG2 documents S2-152388 and S2-152710 and in 3GPP TR 23.720 v0.1.0.